Evaluation of Slickwater Refrac Treatments Utilizing Mechanical and Formation Diversion Techniques ao Extend Wells Productivity

Abstract

The objective of the paper is to evaluate the successful implementation of refrac treatment in unconventional wells with initial completion and stimulation practices. The implementation of refracturing treatment utilizing various diverter systems proved to be operationally feasible, increase productivity, and extend well life cycle. Slick-water refrac practice relies on the combination of adding additional clusters through e-coil within previously stimulated clusters and utilizing mechanical or chemical diverters to plug dominant clusters, allowing the treatment to stimulate newly added or poorly contributing clusters. A fit-for-purpose criteria was developed for proper diverter selection, number and spacing of additional clusters, diverter drop systems, enhanced pumping schedules, and contingency plans. The approach had been utilized in several wells, previously stimulated with various fluid systems and job volumes, completed with different completion types and sizes, and through numerous diverter types and drop systems, with notable success from operational and production point of view. Clear indications of effective diversion and stimulation were observed based on pressure response during diverter drop and treatment cycles, as well as an increased wells productivity. In conclusion, the application of refrac approach proved to be operationally feasible while allowing for an enhanced well performance post the refrac treatment. The implemented combined approach of additional clusters, optimized diverter volumes, adjusted pumping schedules, and multiple diverter drop options offer several benefits in multiple categories: Operational (allowing for on-the-fly addition of diverters and continues cyclic pumping, and preventing the occurrence of screenouts during the refrac treatment), Technical (increasing the stimulated reservoir volume and contact with the formation), and Productivity (enhancing well performance and increasing well life cycle)